CVE-2026-6406: Docker Desktop Enhanced Container Isolation bypass via --use-api-socket CLI flag

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-22 · updated 2026-07-23
Weakness: CWE-863

Description

The Docker CLI --use-api-socket flag bypasses Enhanced Container Isolation (ECI) restrictions in Docker Desktop. When ECI is enabled, Docker socket mounts from containers are denied unless explicitly allowed via the admin-settings configuration. However, the --use-api-socket flag adds the Docker socket mount via the HostConfig.Mounts field rather than the HostConfig.Binds field. The ECI enforcement in the Docker Desktop API proxy only inspected Binds, allowing the mount to pass unchecked. This grants a container full access to the Docker Engine socket and, if the host user has logged in to container registries, their authentication credentials. A local attacker with the ability to run Docker CLI commands can exploit this to escape ECI restrictions, access the Docker Engine, and potentially escalate privileges.

Affected products

Docker Inc. Docker Desktop: from 4.41.0 before 4.59.0 — fixed in 4.59.0

How to fix

Upgrade to a fixed version: Docker Inc. Docker Desktop 4.59.0. Check the vendor advisory for mitigations.

References

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